Saturday, March 12, 2016

Estimation is a Skill for Life.

As you walk around and live your life, imagine if you could easily estimate:
  • how much a bill will be,
  • which item is the best value for money
  • the size, areas and angles of things
Also, it would be great if you could quickly guess how many people are in a room, how many cars in the street, how many boxes on the shelf, or even how many seagulls on the beach?
We are not talking exact answers here, but answers that are good enough for your life.
                             Exact vs Estimate

In mathematics we often stress getting an exact answer.
But in everyday life a few cents here or there are not going to make much difference ... you should focus on the dollars!

Estimation is ...... finding a number that is close enough to the right answer.
You are not trying to get the exact right answer
What you want is something that is good enough (usually in a hurry!)  

                                         Why?
1.Estimation can save you money. Always do a quick estimation of how much you should pay:
Example: you want to buy five magazines that cost $1.95 each. When you go to buy them the cost is $12.25. Is that right?
"five at $1.95 each is about 5 times 2, or about $10"
so $12.25 seems too much!  Ask to have the total checked.
2.Estimation can save you time (when the calculation does not have to be exact)
Example: you want to plant a row of flowers. The row is 58.3cm long. The plants should be 6cm apart. How many do you need?
"58.3 is nearly 60, and 60 divided by 6 is 10,
so 10 plants should be enough."
3. Estimation can save you from making mistakes with your calculator:
Example: you are calculating 107 times 56, and the calculator shows this:
952
Is that right?
"107 times 56 is a bit more more than 100 times 50, which is 5.000"
 Ooops! you must have typed something wrong ...
... in fact you pressed 17×56 (you left out the zero), and without estimating you could have made a really big mistake!

Estimation helps you focus on what is really going on. It helps you to check your Math resolutions as well!
Estimation helps with your Confidence, Judgement and Decisions!

http://www.mathsisfun.com/numbers/estimation-tips-tricks.html

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